We are getting excited about Lagerfest at LRB Riverwalk! We often get the question: What’s the difference between a Lager and an Ale?

The simple answer is yeast. But if you are asking that question, you might need a little more information because you might be comparing a straw golden clear bubbly beverage with a dark amber bubbly beverage and both of those could be a Lager or an Ale.

Introduction of Yeast

So, let’s start at the beginning. ALL beer is made with four ingredients: grains, water, hops, and yeast. In the traditional Lager style, the grains are malted barley, but can be all over the spectrum of flavors. The malting process changes both the flavor and color— light straw that tastes like a cracker to dark as night that tastes like chocolate or coffee.

Once the brewer pulls together the grains, adds water and determines the hops (which can bring another set of different flavors), she will boil this to create a sweet liquid called wort. This wort is cooled and moved to a large fermentation vessel where the brewer will add the last ingredient – yeast.

Just like the grains and the hops, there are different kinds of yeast. The two big families of yeast are Ale yeasts and Lager yeasts:
• Ales are fermented using strains of Saccharomyces cerevisiae, commonly referred to as top-fermenting yeast.
• Lagers are fermented using Saccharomyces pastorianus, also known as bottom-fermenting yeast.

Of course, there is more to this, and we need to step back to where the Lager is from – Bavaria (today’s Germany). Beer goes back to the beginning of civilization, and the people of Bavaria were brewing beer with the resources they had (no FedEx to bring grains from other countries like we have now).


In 1516, the government created the Reinheitsgebot (also known as the Bavarian or German Purity Law). It specified that only malt, hops, and water should be used in beer (They didn’t know all about yeast back then). This law was to protect bread from beer production (limit the use of wheat) so the government could tax the production of beer (not much has changed). Now I know you are going to say, “Wait, I have wonderful German wheat beers!” You are correct, and there was exception for the Royal family who owned the production of German wheat beers. But wheat beers are Ales and that is another blog. ☺

Brewers were only using malt barley, water, and hops and then another law came down in 1553 from Duke Albrecht V that said they could only brew from late September to late April. This was to minimize the risk of fire and spoilage. The beer that was brewed in late April had to last all Summer until they could start brewing again in the Fall. That beer was stored in cool beer cellars. The term “lager” comes from the German for “storage” – that is, to store the beer.

Cold Conditioning

So, the brewers found the yeast that worked best for this longer storage in cooler temperates was the lager yeast or Saccharomyces pastorianus. They also found that as the beer was stored, it underwent a special cold-conditioning phase that created a clean and crisp taste. There was no flavor imparted on the beer from the yeast compared to the common Ale beer. The storage process, which we now call lagering, “cleans up” the beer, leaving a bright, crisp, clear beer.

Today with all the science we can mix and match with all types of ingredients and control the environment unlike the brewers from older times. We lager in our tanks at a cool 55 degrees and it can stay in those tanks for weeks or months.

So there you have it, lager is a different yeast, usually stored in process for a longer time at cooler temperatures. We will continue this discussion with different types of Lagers in out next installment. We look forward to seeing you at Lagerfest in Riverwalk.